Users and developers of networked applications and systems desire reliable, faster and easier to use methods of communicating information between source and destination computer applications and operating environments. Traditional messaging techniques require each application to know the specific serialized format of a message, or require communication between the operating environments of the sender and receiver to provide information or meta-data so that the receiver can interpret the message. Computer users and applications developers are desirous of new methods and computer apparatus for communicating messages which decrease the amount of configuration and runtime overhead involved.
Most distributed computing applications today use synchronous communication technologies, such as remote procedure calls. Such synchronous communications require a sender of a request to wait for a response from the receiver of the request before it can proceed and perform other tasks. The time that the sender must wait depends on the time it takes for the receiver to process the request and return a response. Synchronous communication mechanisms also require the sender and the receiver to be operating simultaneously.
In contrast, using asynchronous communications, senders make requests to receivers and can move on to perform other tasks immediately. If a response is expected back from the receiver, it is up to the original sender to decide when it will actually look for and process the response. Most importantly, there is no guarantee that receivers will process requests within any particular period of time. In fact, with asynchronous communications, there are no requirements that receivers be running nor even the communications infrastructure be available in order for a sender to initiate a request.
Message queuing systems implement asynchronous communications by enabling applications to send messages to and receive messages from other applications. These applications may be running on the same machine or on separate machines connected by a network. When an application receives a request message, it processes the request by reading the contents of the message formatted in a known pattern and acting accordingly. If required, the receiving application can send a response message back to the original requestor.
Many applications are now using message queuing networks for the enhanced communication delivery reliability between networked computer systems provided by sending messages asynchronously across a message queuing enterprise network. However, these messages are simply received as type-less buffers of raw data that are passed between applications. In some instances, these messages have additional signaling information attached that describe how the message should be sent by the underlying sub-system. However, the messages do not provide any semantic information that enables the message recipient to interpret the meaning of the message contents. To communicate, the source and destination applications rely either on private message content encoding schemes or prior arrangements between the applications to only send messages of a certain type.